condition mean min max ZT0-3 7.6926749999999995 7.6926749999999995 7.6926749999999995 ZT4-7 5.94771 5.94771 5.94771 ZT8-11 5.494455 5.494455 5.494455 ZT12-15 5.198515 5.198515 5.198515 ZT16-19 8.16643 8.16643 8.16643 ZT20-23 6.93168 6.93168 6.93168